The present invention relates generally to integrated circuits, and more specifically to a text-to-speech conversion system on a single integrated circuit.
The conversion of text into speech has become increasingly important with the emergence of data communication and other new applications. Most data is stored and provided in a digital format that can be more easily processed and manipulated by digital processing means. The digital data may need to be converted to an analog format for speech that is intelligible to humans. Text-to-speech conversion is a process whereby data in a particular digital format (e.g., ASCII text) is converted into a particular analog format (e.g., speech) suitable for reception by humans.
Many conventional text-to-speech conversion systems are based on a pure software implementation that requires (1) a powerful processor to perform various computation and translation tasks, (2) a large memory to store an inventory of speech sounds, and (3) possibly other peripherals such as sound cards. For example, U.S. Pat. No. 5,878,393 describes a “high quality concatenated reading” system comprised of a central processing unit (CPU), a random access memory (RAM), a disk storage system, a sound card, and so on. This system is suitable for implementation on a personal computer (PC) system having all of these required hardware elements. Other text-to-speech conversion systems, such as those described in U.S. Pat. Nos. 5,634,084 and 5,636,325, are also based on the use of PC systems.
PC-based text-to-speech conversion systems such as those identified above are not well suited for many modern-day applications where processing power may be limited and device size may be a major design consideration. Such applications may include, for example, portable devices (e.g., personal digital assistance or PDA), mobile communication devices (e.g., cellular phones, pagers), consumer electronics, and so on. For these applications, size, cost, and power consumption may all be important design considerations that would preclude the use of conventional pure software-based text-to-speech conversion systems.
As can be seen, a text-to-speech conversion system that can be used for a wide variety of applications, such as those listed above, is highly desirable.